bf16 matmul's corresponding `tensor.pack` not properly optimized

[yifeizh2]

Currently, the following 2 single-layer MLP have worst performance compared with GC v1.

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dtype	batch size	hidden list	GC V1	8c55a05 remove brgemm read lock
bf16	128	1024x1024	0.0286	0.0828
bf16	128	1024x512	0.0204	0.0670

We performed detailed breakdown as follows:

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128x1024x1024	GC v1	8c55a05
matmul only	0.01766	0.01989
tiled pack (or reorder)	0.02634	0.04632
total	0.04418	0.077969

and

<style> </style>

128x1024x512	GC v1	8c55a05
matmul only	0.01587	0.01591
tiled pack (or reorder)	0.01278	0.0398
total	0.02881	0.06917

Are there any further optimization opportunity for vnni pack?

[BRUCE11111]

VNNI reorder will be included in my to-do list. However, the current priority is to merge the physical register pass and the corresponding vector-based op fusion under static shape into master as soon as possible (within two weeks). Then support dynamic shape for the sake of another issue, and then optimize the instruction level of specific op like vnni reorder. I can switch priorities if there is a more urgent need.

[ZhennanQin]

I guess those VNNI reorder can be folded out if we have constant weight cache support? @niuxiaog Can you try to enable weight cache for both bench-gc and OV integration?

[niuxiaog]

I'm working on enabling it with OV and may finish in this week. For bench-gc, maybe next week.

[lmontigny]

waiting for dynamic shape